Synthesis,Spectral, and Electrochemical Properties of meso‐5,10,15,20‐Tetrakis (2′‐chlorobenzoquinolin‐3′‐yl)porphyrins

The synthesis, characterization, and redox and spectral properties of the meso‐5,10,15,20‐tetrakis(2′‐chlorobenzoquinolin‐3′‐yl)porphyrin are reported. The synthesis of the porphyrin was performed by following the modified Lindsey procedure, and its zinc(II) derivative was prepared by using the conventional method. The electronic properties of the compound were investigated by cyclic voltammetry and spectroscopy. This compound shows unusual redox behavior with difficulty in oxidation and ease of reduction compared to tetraphenylporphyrin.     

The resistance of metallic plates to localized impulse

The responses of metallic plates and sandwich panels to localized impulse are examined by using a dynamic plate test protocol supported by simulations. The fidelity of the simulation approach is assessed by comparing predictions of the deformations of a strong-honeycomb-core panel with measurements. The response is interpreted by comparing and contrasting the deformations with those experienced by the same sandwich panel (and an equivalent solid plate) subjected to a planar impulse. Comparisons based on the center point displacement reveal the following paradox. The honeycomb panel is superior to a solid plate when subjected to a planar impulse, but inferior when localized. The insights gained from an interpretation of these results are used to demonstrate that a new design with a doubly-corrugated soft core outperforms solid plates both for planar and localized impulses.     

The dynamic response of clamped rectangular Y-frame and corrugated core sandwich plates

The dynamic response of fully clamped, monolithic and sandwich plates of equal areal mass has been measured by loading rectangular plates over a central patch with metal foam projectiles. All plates are made from AISI 304 stainless steel, and the sandwich topologies comprise two identical face-sheets and either Y-frame or corrugated cores. The resistance to shock loading is quantified by the permanent transverse deflection at mid-span of the plates as a function of projectile momentum. At low levels of projectile momentum both types of sandwich plate deflect less than monolithic plates of equal areal mass. However, at higher levels of projectile momentum, the sandwich plates tear while the monolithic plates remain intact. Three-dimensional finite element (FE) calculations adequately predict the measured responses, prior to the onset of tearing. These calculations also reveal that the accumulated plastic strains in the front face of the sandwich plates exceed those in the monolithic plates. These high plastic strains lead to failure of the front face sheets of the sandwich plates at lower values of projectile momentum than for the equivalent monolithic plates.     

Wireless Coupling of Conducting Polymer Actuators with Light Emission

Combining the actuation of conducting polymers with additional functionalities is an interesting fundamental scientific challenge and increases their application potential. Herein we demonstrate the possibility of direct integration of a miniaturized light emitting diode (LED) in a polypyrrole (PPy) matrix in order to achieve simultaneous wireless actuation and light emission. A light emitting diode is used as a part of an electroactive surface on which electrochemical polymerization allows direct incorporation of the electronic device into the polymer. The resulting free-standing polymer/LED hybrid can be addressed by bipolar electrochemistry to trigger simultaneously oxidation and reduction reactions at its opposite extremities, leading to a controlled deformation and an electron flow through the integrated LED. Such a dual response in the form of actuation and light emission opens up interesting perspectives in the field of microrobotics.     

CP violating rate asymmetries in B decays

We briefly discuss measurements of angles β and α of the unitarity triangle. We then review rate asymmetries usingSU(3) relationships in the standard model (SM). Some methods to measure angle y usingSU(3) are then discussed. We note that rate forb → sγ can be used to set limits on extra dimensions in which standard model particles propagate.     

LIGHT INDUCED INTERACTION BETWEEN RHODOPSIN AND GTP DEPENDENT PROCESSES IN ROD OUTER SEGMENTS—I. KINETIC ANALYSES OF LIGHT SCATTERING TRANSIENTS

Abstract— A fast light-induced light scattering transient in the presence of Mg²⁺ and GTP is observed from bovine rod outer segment suspension. This transient is studied at various temperatures, degrees of photo-bleaching and GTP concentration. The kinetic analysis of this signal at low photo-bleaching (∼ 5%) reveals two different processes which are consecutive rather than simultaneous. The rate of both processes depends upon the extent of photo-bleaching and indicates that each process requires a photolyzed rhodopsin intermediate. At low temperature, the rate constant of both the processes increases with the extent of photo-bleaching while at higher temperatures it decreases. The calculated activation energy of both processes decreases with increasing photo-bleaching. It has also been observed that with decreasing GTP concentration, the rates of both processes decrease indicating that the two processes though first order are most likely bimolecular, first order in both GTP and the photolytic rhodopsin intermediate (metarhodopsin II)     

Dielectric relaxation and related studies of 4-ethylphenol-methanol mixtures using time domain reflectometry

The dielectric relaxation studies of 4-ethylphenol-methanol mixtures have been carried out at various temperatures ranging from 10°C to 40°C using time domain reflectometry in the frequency range 10 MHz to 10 GHz. The relaxation mechanism in these systems is explained by Cole-Davidson model. The excess dielectric parameters, Kirkwood correlation factor and activation energy have been calculated and discussed with respect to molecular arrangements, and microdynamics of the binary mixture composed of both the associative type of liquids.     

Higher-dimensional cosmological model with variable gravitational constant and bulk viscosity in Lyra geometry

We have studied five-dimensional homogeneous cosmological models with variableG and bulk viscosity in Lyra geometry. Exact solutions for the field equations have been obtained and physical properties of the models are discussed. It has been observed that the results of new models are well within the observational limit.